Unless otherwise indicated herein, the materials described in this section are not prior art to the claims in this application and are not admitted to be prior art by inclusion in this section.
Various technologies can be utilized to display information to a user of a computing system. Some systems for displaying information may utilize a screen (such as a liquid crystal display (LCD) screen or plasma display screen) integrated into a portable device such as a mobile phone or audio playback device that can be moved, on demand, into a position by a user at which the screen is viewable. Other systems for displaying information continuously to a user may utilize head-mounted displays. A head-mounted display can be incorporated into a pair of goggles, glasses, a headband, a helmet, or other such device that the user can wear. A head-mounted display is typically positioned near the user's eyes and calibrated and/or aligned to the user's field of view to allow the user to review displayed information with little or no head movement. The display may also be transparent or translucent, allowing the user to view and interact with the surrounding environment while wearing the head-mounted display. In some cases, the display may not be transparent, but may project a captured image of the environment on the display to simulate transparency or translucency. In other cases, the display may be formed directly on a user's retina via a low-powered laser scanning technique. To generate display information such as images and text for display, a computer processing system may be used. Such head-mounted displays have a variety of applications, such as aviation information systems, vehicle navigation systems, information display/interaction, social networking, and video games, among others.
For example, in aviation information systems, display information may include airspeed, altitude, a horizon line, heading, turn/bank, and slip/skid indicators. Display information may also include aviation data and symbols for use in approaches and landings. For example, a flight guidance system in the head-mounted display can provide visual cues based on navigation aids such as an Instrument Landing System or augmented Global Positioning System. Other aviation uses are possible as well. In the automotive field, display information may include speedometer, tachometer, and navigation system displays. Additionally, night vision information may be displayed to aid in night driving. Other automotive uses are possible as well.
As more and more applications and uses are being developed for head-mounted display devices, and computing systems in general, more complex interactions have arisen. For example, in the aviation context, a pilot may need to interface with the information being displayed in the head-mounted display, perhaps to switch between a parameter display interface (e.g., displaying airspeed, altitude, a horizon line, heading, etc.) and an approach/landing display interface.
Other, more complex interactions may also be necessary. For example, a pilot may wish to interact with other pilots in the sky and/or send information to one or more selected pilots, or a driver may wish to interact with other drivers on the road or other passengers in the car. Current solutions, such as buttons, are limited in their functionality, and generally increase bulk, block light, and/or reduce peripheral vision due to their size, location, and composition requirements.